android 圓形展開/關閉動畫

參考自：高仿嗶哩嗶哩客戶端的SearchView http://www.jianshu.com/p/e0a6fc621945

開關點擊：

CircleAnimateUtils.handleAnimate(txt);

圓形動畫工具類：

public class CircleAnimateUtils {
    public static void handleAnimate(final View animateView) {
        //隱藏
        if (animateView.getVisibility() == View.VISIBLE) {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
                /**
                 * createCircularReveal 方法參數
                 * view 執行動畫的view
                 * centerX 圓心橫座標
                 * centerY 圓心縱座標
                 * startRadius 動畫開始時圓的半徑
                 * endRadius 動畫結束時圓的半徑
                 */
                final Animator animatorHide = ViewAnimationUtils.createCircularReveal(animateView,
                        0,
                        0,
                        //確定圓的半徑（算長寬的斜邊長，這樣半徑不會太短也不會很長效果比較舒服）
                        (float) Math.hypot(animateView.getWidth(), animateView.getHeight()),
                        0);
                animatorHide.addListener(new Animator.AnimatorListener() {
                    @Override
                    public void onAnimationStart(Animator animation) {

                    }

                    @Override
                    public void onAnimationEnd(Animator animation) {
                        animateView.setVisibility(View.GONE);
                    }

                    @Override
                    public void onAnimationCancel(Animator animation) {

                    }

                    @Override
                    public void onAnimationRepeat(Animator animation) {

                    }
                });
                animatorHide.setDuration(300);
                animatorHide.start();
            } else {
                animateView.setVisibility(View.GONE);
            }
            animateView.setEnabled(false);
        }
        //顯示
        else {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
                final Animator animator = ViewAnimationUtils.createCircularReveal(animateView,
                        0,
                        0,
                        0,
                        (float) Math.hypot(animateView.getWidth(), animateView.getHeight()));
                animator.addListener(new Animator.AnimatorListener() {
                    @Override
                    public void onAnimationStart(Animator animation) {
                        animateView.setVisibility(View.VISIBLE);
                    }

                    @Override
                    public void onAnimationEnd(Animator animation) {

                    }

                    @Override
                    public void onAnimationCancel(Animator animation) {

                    }

                    @Override
                    public void onAnimationRepeat(Animator animation) {

                    }
                });
                animator.setDuration(300);
                animator.start();
            } else {
                animateView.setVisibility(View.VISIBLE);
            }
            animateView.setEnabled(true);
        }
    }
}